Railway signaling



C. W. DUNHAM.

' RAILWAY SIGNALING. v APPLICATION FILED MAR.26,.1'920y.

' Patnted Jim 7, 1921.

AN MN INVENTOR.

Q'K'f HIS ATTORNEY Ul 'TT' ra t CHARLES W. D'UNHAM, OF FAIRMON'I', PENNSYLVANIA, ASSIGNOB TO THE UNION SWITCH & SIGNAL COMPANY, OF SWISSVALE, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

issoass.

Specification of Letters Patent.

Patented June 7, 1921.

Continuation of application Serial No. 323,247, filed September 12, 1919. This application filed March 26, 1920. Serial No. 368,873.

T 0 (M whom it may concern Be it known that 1, CHARLES W. DUNHAM,

a citizen of the United States, residing at ljairmont, in the county of Allegheny and fta'tate of Pennsylvania, have invented certain new and useful Improvements in Railway Signaling, of which the following is a specification.

My invention relates to electrical apparatus, and particularly to apparatus comprising a polarized relay, a circuit for said relay including a source of current and a pole changer, and a second circuit controlled by the polarized relay.

One object of my invention is the provision of means for reducing the interval of time during which the second circuit is open while the polarized relay is responding to a reversal of the pole-change Apparatus embodying my invention is particularly well adapted TO the control of signals and other devices for governing the passage ofcars or trains along a railway, although it is not limited to such adaptation.

The present application is a continuation 'of my co-pending application, filed September 12, 1919, Serial No. 3232 17, for railway signaling.

I will describe two forms of apparatus embodying my invention, and will then point out the novel features thereof in claims. I

In the accompanying drawings Figure 1 is a diagrammatic View showing a signaling system having a signal controlled in accordance with one form of my invention, the holding magnet being a slow-releasing magnet having a very short time element. Fig. 2 is a fragmentary view similar to a portion of Fig. 1 but showing a modified form of apparatus in which theholding magnet is non-slow-releasing in character.

Similar reference characters refer to simi lar parts in each of the views.

Referring first to Fig. 1, the reference characters 2 and 2* designate the track rails of a railway over which traflic normally moves in the direction indicated by the arrow. These rails are divided by insulated joints 3 into a plurality of sections of'which only one section AB is shown in the drawing. The section A-B is provided with a track circuit comprising, as usual, the track rails of the section, a battery 5 connected across the rails at the exit end of the section, and a track relay 6 connected across the rails at the entrance end ofthe section.

Located adjacent the entrance end of section A-B is a signal S governing trafiic through this section, and arranged to. indicate stop, caution and proceed. This signal is controlled by a polarized relay R, which, in turn, is controlled by the track relay 6 and by a pole-changer E operated by a signal S located at the entrance end of the section to the left of section A-B. The circuit for this polarized relay R is from a battery 39, through wire 7, pole-changer P, wire 8, contact 9 of track relay 6, wiresso that current of normal polarity is sup-- plied to relay E. This current causes the polarized contact 28 to close. Of course, when track relay 6 is open, as shown in the drawing, relay R is deenergized, so that its neutral front contact 15 is open and its neutral back contact 34 is closed. Relay R is so constructed that when it becomes deenergized after having been energized by current of normal polarity, the polarized con tact 28 remains closed.

The signal S comprises a semaphore 4 biased to the stop position, an electric motor M for moving the semaphore to the caution and proceed positions, and a holding mag net H for holding this semaphore in the two last-mentioned positions. This magnet H is a slow-releasing magnet having a very short time element. 7

The operation of the parts thus far referred to, is as follows:

SectionA-B is occupied by a car or train represented by a pair of wheels and an axle V, so that track relay 6 is open and polarized relay R is deenergi'zed. All circuits for the control of the motor and holding magnet for signal S are, consequently, open, so that'the semaphore 4 of this signal is in the stop position. I will now assume that the car or train V passes out of section and into the section next to the left. 'l raclr relay 0 then closes, but the movement -r to the stop position due to the 0 next section causes pclechanger so that current 02 re verse 1 clar ty is so ied to relay The neutral .nt l5 of this relay then close a circuit through the holding magnet H which circuit is from battery 10, th ough .econ 15, v l6 '1. l and 18, contact 1.0- 15), wire 20, magnet and wires 2i and 23 to battery 40. Contact 15 of relay hi, this circuit being from battery 4L0, through wires 14; and contact 15, wires "7 and 24., contact 20 -25, wire 26, mo-

l wires 2! and to battery 40. hen operates to move semaphore to its caution or inclined position, at which point the circuit for the motor is opened because the wiper 25 passes oil of the ed contact number 25. The signal is heldin the caution position, however, by magnet l-l, which contnnies to bc energized.

'When the car or train in the section to the left of section A- -lB passes out of such section, signal S will move to the caution or proceed position, so that pole-changer l. will be reversed, whereupon current of normal polarity will be supplied to the polarized relay R, causing contact 28 of this relay to close. The reversal of the polarity of the current supplied to relay R causes contact 15 to open momentarily, thus momentarily opening the circuit for magnet H; for present purp ses, however, I will assume that this does not cause magnet H to release the semaphore a from tie caution position. A new circuit for motor M is then closed, this circuit being from battery so, through wires l .-l and 14, contacts 15 and 28, wires 29 and 31, contact 25"-25, wire 26, motor M, and wires 2'? and 23 to battery 40. The motor M then moves the semaphore toward the proceed position, the mzz uct being energized during the first of such movement by the same circuit )efore. After the semaphore has moved iort distance, however, new circuit for D becomes closed at contact 19-l9, tins circuit being from battery 40 through wires 1% and let, contact 15, polarized contact 28, wires 29 and 30, contact 19 19, wire Q0, magnet H, and wires 21 and 23 to battery 40. When the semaphore reaches the proceed position, the wiper 25 passes ofi' of contact segment 25", so that the motor becomes deenergizcd. The semaphore is hold in this position, however, by magnet H.

The operation of the signal S when acar or train enters section fit-l3, will bet.

it also closes a circuit for motor extremely small and almost, immeasurable) as relay it closes.

larized relay R is reversed, the neutral front contact 15 of this relay is momentarily opened. The time element or lag of magnet H is less than the time contact 15 is open during the reversal of pole-changer P, andso it follows that during this reversal magnet ll will release unless means are provided to prevent such action. The means here shown for preventing the release of the holding magnet comprises an auxiliary relay G, which relay is connected in multiple with relay R and is controlled by a neutral back contact 3% of the latter relay. The circuit for this relay C is from battery 39, through wire 7, pole-changer P, wire 8, contact 9, wires 10 and 32, relay U, wire 33, contact S l, wire 12, pole-changer P, and wire 18 to battery 89. The caution circuit for holding magnet H is provided with a branch around contact 15 of the polarized relay it, which branch passes from wire 14, through wire 38, front contact 37 of auxiliary relay C, and wire 36 to wire 17.

T is operation of this portion of the apparatus is as follows. It is, of course, understood that when pole-changer P reverses, the time interval during which the circuit for relay 1% is open is very short, being in fact only a small fraction of a second. Furthermore, the characteristics of relay R and the circuit in which it is included are such that when the polechanger reverses, back contact 34- closes at substantially the same instant that the circuit for relay R is reclosed at the pole-changer. Relay C will therefore close v ry soon after back contact 15: and the closing of back contact 34 during reversal of pole-changer P (which time is 7 plus the time required for contact 37 to close after contact 3% closes. When the parts are so designed, it is evident that magnet Hv will not release the signal while relay R is open due to reversal of pole-changer P. I have found that the desired result may be secured by making the time element of magnet H as small as 0.15 second, which is considerably less than the time that contact 15 is open during reversal of the polechanger. llelay C, of course, opens as soon The main advantage of my invention lies in the fact that when a train enters a section, the signal for such section responds by m0vsignal (i is in the caution position and the to the stop position much more quickly polarity of the current supphed to the pothan 15 the case when a slow-releasing magll is on short circuit.

Referring now to Fig. 2, the partshei'e shown are the same as the corresponding parts shown in Fig. 1, except that the magnet H is non-slow-releasing in character,

and means are provided for placing this 7 magnet on short circuit while the signal is in the caution position and the back contacts of relay R and G are closed. The short circuit path for magnet H is from one terminal of this magnet through wires 21 and 22, wire 41, back contact 42 of relay C, wire -13, back contact 15 of relay R, wires 16,17 and 18, contact 1919, and wire 20 5c magnet l-l. The control of the relays B and C is the same as in Fig. 1, and the control of the signal by these relays is likewise the same as in Fig. 1, except for the short-circuiting feature.

As stated above in discussing Fig. 1, after current is supplied to relay C a certain interval of time elapses before front contact 37 closes. The greater part of this interval is consumed in setting up flux in the magnetic circuit of the relay, however, and during this part of the interval back contact l2 remains closed. The interval between the opening of back contact 4 2 and the closing of front contact 37 is so extremely small that it cannot readily be measured. It will be seen, therefore, that during the greater part of the time interval of relay C, magnet t is well understood that when a magnet is deenergized and is immediately placed on short circuit it will hold its armature for a considerable interval of time, this interval being longer than the interval between the closing of back contact 15 and the opening of back contact 412.

As for relay R, the interval of time between the opening of the front point of contact 15 and the closing of the back point of this contact is extremely short-too short to be readily measureable.

It will now be seen that magnet H is on open circuit during the tim between the opening of the front point of contact 15 and the closing of the back point of this contact, that the magnet is on short circuit during the interval between the closing of the back point of, contact 15 and the opening of back contact 42, and that it is on open circuit, during the time between the opening of back contact 12 and the closing of front contact 37. I have found that an &

ordinary quick releasing magnet will hold its armature during this cycle of operations.

The real difference between Figs. 1 and 2, is, of course, that in Fig. 2 the time int-erval of relay C is virtually eliminated insofar as its effect on the holding magnet is concerned by placing this magnet on short circuit during such interval.

Although I have herein shown and de scribed only two forms of apparatus em bodying my invention, it is. understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what 1 claim is: V

1. In combination, apolarized relay, a circuit for said relay including a source of current, means for reversing the polarity of the current supplied to said relay from said source, a second relay, a circuit for said second relay controlled by a neutral back contact of said polarized relay, means 'for opening and closing said two circuits simultaneously, and another circuit controlled by a neutral front contact of said polarized relay and a front contact of said second relay in multiple.

2. In combination, apolarized relay, acircuit for said relay including a source of current, means included in said circuit for reversing the polarity of the current supplied to said-relay from said source, a second re lay, a circuit for said second relay includ ing said source of current and a neutral back contact of said polarized relay, and another circuit controlled by a neutral front contact of said polarized relay and a front contact of said second relay in multiple.

3. In combination, a polarized relay, a circuit for said relay including a source of current, means included in said circuit for reversing the polarity of the current supplied to said relay from said source, a second relay, means controlled by said polarized relay for energizing said second relay when the polarized relay is open during response of the latter relay to reversal of the polarity of the current supplied thereto, and

a circuit controlled by a neutral front contact of said polarized relay and a front contact of said second relay in multiple.

1. In combination, a polarized relay, a circuit for said relay including a source of current, means included in said circuit for reversing the polarity of the current supplied to said relay from said source, a second relay, means controlled by said polarized relay for energizing said second relay when the polarized relay is open during response of the latter relay to reversal of the polarity of the current supplied thereto, a signal having a semaphore biased to one position and a magnet for holding'the semaphore in an- &

other position against the biasing force, and a circuit for said magnet controlled by a neutral front contact of said polarized relay and a front contact of said second relay in multiple.

5. A signaling system comprising a section of railway track, a track circuit for said section including a track relay, a polarized relay controlled by said track relay, means controlled by traffic conditions in advance of said section for supplying said polarized relay with current of one polarity or the other, a signal for said section controlled by neutral and polarized contacts of said polarized relay, an auxiliary relay connected in multiple with said polarized relay and controlled by a neutral back contact of the latter relay, and a branch around the neutral contact of said polarized relay in the circuits for said signal said branch including a front contact of said auxiliary relay.

6. In combination, a polarized relay, a circuit for said relay including a source of current, means included in said circuit for reversing the polarity of the current supplied to said relay from said source, a second relay, means controlled by said polarized relay for energizing said second relay when the polarized relay is open during response of the latter relay to the reversal of the polarity of the current supplied thereto, a signal controlled by a neutral front contact of said polarized relay and a front contact of said second relay-in multiple, and means including a back contact or each of said relays for placing said signal on short circuit.

7. In combination, a polarized relay, a circuit for said relay including a source of current, means included in said circuit for reversing the polarity of the current supplied to said relay from said source, a second relay, means controlled by said polarized relay for energizing said second relay when the polarized relay is open during response of the latter relay to reversal of the polarity of the current supplied thereto,

a signal having a semaphore biased to one position and a magnet for holding the semaphore in another position against the biasing force, a circuit for said magnet controlled by a neutral front contact of said.

polarized relay and a front contact of said second relay in multiple, and means for placing said magnet on short circuit comprising a back contact on each of said relays.

8. In combination, a polarized relay, a circuit for said relay including a source of current, means for reversing the polarity of the current supplied to said relay from said source, a second relay, a circuit for said second relay controlled by a neutral back contact of said polarized relay, means for opening and closing said two circuits simultaneously, and a signal controlled by a neutral front contact of said polarized 'relay and a iront contact of said second relay in multiple.

9. In combination, a polarized relay, a

circuit for said relay including a source of current, means included in said circuit for reversing the polarity of the current supplied to said relay from said source, a second relay, a circuit for said second relay including said source of current and a neutral back contact of said polarized relay, and a signal controlled by a neutral front contact of said polarized relay and a front contact of said second relay in multiple,

10. In combination, a polarized relay, a circuit for said relay including a source of current, means included in said circuit for reversing the polarity of the current supplied to said relay from said source, a second relay, means controlled by said polarized relay for energizing said second relay when the polarized relay is open during response of the latter relay to reversal of the polarity of the current supplied thereto, and a signal controlled by a neutral front contact of said polarized relay and a front contact of said second relay in multiple.

In testimony whereof I afiix my signature.

CHARLES W. DUNHAM. 

